Hah, yeah, had some that were zipped, containing doc file containing jpeg screenshots from cameras 😀
Wouldn’t be rar. Too obscure for them.
Anyway, long winded, but if it’s just one page PDF you can use Foxit Reader (much better than Acrobat by the way), and use the snapshot tool, select the page and it’s copied to the clipboard. Paste into something else to create the JPEG (I recommend Paint.NET).
There’s probably a way of printing to JPEG with the right software also. Though far easier to print to PDF. In fact, could you ditch the crazy software and do this anyway? Windows 10 has a built in PDF printer. Foxit Reader also has a PDF printer. If you have lots of things to go into one PDF, Bullzip PDF printer can let you append into one.